Page 2, bottom right: If control points are placed
non-uniformly in ray direction, the resulting v parameter may
have a large margin of error because the algorithm computes v
in 2D space. To compensate this, we should add a subexpression
about z in the maximum depth computation. (Thanks to Emil
Kirichev)

Page 4, Figure 5: "c" in "Vector p = c.evaluate(v);"
should be the whole curve because "v" is computed for
it. (Thanks to Emil Kirichev)